The present invention teaches a system of using a camera to track handwriting and determine certain characteristics of the handwriting. More specifically, the present system shows a first embodiment with a monocular way of tracking the movement of the pen and also a camera-based way of identifying a person""s identity.
Advances in computer technology have given rise to smaller computing systems. As the computing structure becomes smaller, the size of the keyboard and the size of the screen become a real limit on the size of the computer. For example, the laptop computer cannot be easily made smaller than the keyboard. One solution is to use data entry via handwriting. Many handwriting systems use a tablet that detects the pressure of the pen. The pressure-sensitive tablets, however, are specialized materials in themselves and take up space.
Security is an important issue in current information technology, and it is highly desirable to be able to identify a person using biometric aspects. Various people have suggested different biometric techniques, including face recognition, fingerprint recognition, iris recognition, and others.
The present inventors disclose systems which use a video camera to capture the motion of the hand and translate that motion into handwriting. The principles are described in U.S. patent application Ser. No. 081,490,678, now U.S. Pat. No. 6,044,165. This system uses an image acquisition device, e.g. a camera, a writing surface, e.g., a piece of paper, and a writing implement, e.g. a normal pen, as the data entry device. The only necessary hardware that is not common is the camera. However, cameras can be made much smaller than keyboards.
During processing of the system, the inventors found that it is advantageous to determine when the pen is up and when the pen is down. One aspect of the present system describes a way of tracking when the pen is up and down using a monocular system.
Another aspect uses both the pen up and pen down strokes to form an identification technique using biometric techniques. The present system also describes a special way of verifying identity using signature verification and special features in the signature verification.